Hassi Khebi 001, Rare Ungrouped Carbonaceous C3, Micromount

$6.00
Adding to cart… The item has been added

Hassi Khebi 001 meteorites were recovered out of the Tindouf province of Algeria in 2022. Many small broken stones and fragments were found. They had a distinctively frothy fusion crust and broken surfaces showed many tiny chondrules, CAI's, and clasts contrasted against a charcoal-black matrix. Analysis and classification took place at UNM by Dr. Carl Agee. As expected, this meteorite was a carbonaceous chondrite, but the oxygen isotope plot placed it outside the domain of known carbonaceous classes. The official classification is "C3-ungrouped" and it is one of only 31 known meteorites of this type. 

Visually, this meteorite resembles an aesthetically-pleasing carbonaceous matrix that is not unlike Allende or Murchison, except with fewer CAI inclusions. The fusion crust and matrix is relatively fresh, so while this is not a recent fall, it is not an ancient weathered example either. For collectors, this is a good example of a rare/exotic type and it represents the first catalog entry on a new dense collection area (Hassi Khebi).

Refer to the photo. The black centimeter cube is shown for scale and is not included. You are purchasing a small fragment like the one shown. Your purchase will include a labeled gemjar for safe storage.

From the Meteoritical Bulletin entry on Hassi Khebi 001 :

Hassi Khebi 001 29°09’28.3"N, 4°55’43.3"W

Tindouf, Algeria

Purchased: 2022

Classification: Carbonaceous chondrite (C3, ungrouped)

History: Purchased by Matthew Stream from an Algerian meteorite dealer in August 2022. Found approximately 15 km southeast of Hassi Khébi in Tindouf Province, Algeria.

Physical characteristics: Dark gray/black fusion-crusted exterior, saw cut surface reveals scattered well-formed chondrules set in a black matrix that makes up over 50% of this meteorite. Some of the chondrules appear to have orange iron-staining. Rare small CAIs are visible.

Petrography: (C. Agee and M. Spilde, UNM) Electron microprobe examination reveals a fine-grained matrix that gives slightly low microprobe totals (~95%) consistent with the absence of significant hydrous phases. Most chondrules are porphyritic type I with predominantly forsteritic olivines and enstatitic pyroxenes. Apparent mean chondrule diameter is 275±227 μm (n=50). Kamacite and Fe-Ni sulfide are the dominant opaque phases. Cr-magnetite was not detected. Vesicular fusion crust is 200-300 µm thick.

Geochemistry: (M. Spilde and C. Agee, UNM) Type I chondrule olivine Fa1.3±1.4, Cr2O3=0.34±0.16 (wt%) n=24; low-Ca pyroxene Fs1.6±0.8Wo1.6±1.5, n=9; matrix (20 μm defocused microprobe beam) SiO2=31.5±5.3, TiO2=0.32±0.66, Cr2O3=0.43±0.14, Al2O3=4.4±3.6, FeO=29.6±9.7, MgO=15.7±3.7, CaO=3.0±3.4, NiO=1.6±0.3, MnO=0.21±0.07, Na2O=0.18±0.05, K2O=0.27±0.15, SO3=7.3±3.6 (all wt%), n=7., with total around 95 wt% not consistent with significant hydrous phases being present. Fusion crust, proxy from bulk composition (20 µm defocused microprobe beam) SiO2=43.5±2.5, TiO2=0.17±0.01, Cr2O3=0.58±0.04, Al2O3=4.2±0.5, FeO=19.5±4.0, MgO=28.2±2.5, CaO=3.1±0.3, NiO=0.10±0.07, MnO=0.35±0.01, Na2O=0.83±0.12, K2O=0.07±0.01 (all wt%), n=7. Oxygen isotopes (K. Ziegler, UNM): 3 acid-washed fragments analyzed by laser fluorination gave δ17O=-6.509,-7.235,-9.497; δ18O=-1.497, -2.483, -5.165 (all ‰).

Classification: Carbonaceous chondrite ungrouped (C3). Oxygen isotopic compositions are significantly displaced below the CCAM indicating ungrouped carbonaceous chondrite. Type 3 based on a predominantly anhydrous matrix and Cr2O3 content of olivine.